Mitigation of Single-Point-of-Failure: Development of M127A1 White Star Illuminant Compositions Containing an Epoxy Binder System

Hand-held signals (HHS) are used in signaling troop movements and aircraft. Meant to attract attention and to identify the positions of military personnel, HHS technologies find use in both training exercises and combat situations, and improvements are being sought to advance existing HHS technology. One of the most popular HHS items used by the US military for illuminating purposes is the M127A1 white star parachute, consisting of approximately 85 g of illuminant composition with a minimum burn time of 25 s and a minimum luminous intensity of 90000 cd. At this time, there is no dominant wavelength or spectral purity requirement for this illuminant. The current M127A1 HHS illuminant formulation fielded by the US Army consists of magnesium, powdered sodium nitrate, and Laminac 4116/ Lupersol polyester binder system. The result of this mixture is an intense and bright burning flame, due to the formation of white-light-emitting incandescent magnesium oxide (MgO) particles, and the presence of atomic sodium (Na), which is a very intense emitter of yellow light [1] . Although the in-service M127A1 HHS illuminant is successful in achieving the military specifications, Laminac 4116/Lupersol is not an ideal binder system. The binder system is a single-point-of-failure, contains a suspected carcinogenic material (styrene monomer) [2] , and has a limited shelf-life [3] . Because Laminac 4116/Lupersol binder system is currently the binder present in all HHS illuminating compositions, failure to replace this single-point-of-failure binder system poses a significant risk to the future of these pyrotechnic signaling munitions remaining in the arsenal of the warfighter. Without HHS illuminants in the warfighter’s arsenal, combat readiness and survivability is at risk. In a recent paper, the use of epoxy-based binder system Epon 813/Versamid 140 was found to be a non-energetic binder than Laminac 4116/Lupersol binder system, thus prolonging the burn time of red -and green-light-emitting illuminant compositions [4] . Although longer burn times are known to reduce luminous intensity values, it was believed that altering oxidizer/fuel/binder percentages would be beneficial in raising luminous intensity values in the presence of the Epon 813/Versamid 140 binder systems. Epon 813/Versamid 140 binder systems was thought to be a suitable choice in the development of a suitable M127A1 illuminant composition because the binder system is widely commercially available, thus mitigating concerns associated with single-point-of-failure. Moreover, the Epon 813/Versamid 140 has a proven history of working well as a replacement for the Laminac 4116/Lupersol binder system. It was the binder system of choice in redand green-light-emitting illuminating signaling formulations, which were recently proven out at the prototype level [5]. In addition to mitigating single point-of-failure concerns, it was also of interest to minimize the hygroscopic nature associated with powdered sodium nitrate-based illuminants. Despite its strong oxidizing abilities and its tendency